NHTSA Interpretation File Search
Overview
NHTSA's Chief Counsel interprets the statutes that the agency administers and the standards and regulations that it issues. Members of the public may submit requests for interpretation, and the Chief Counsel will respond with a letter of interpretation. These interpretation letters look at the particular facts presented in the question and explain the agency’s opinion on how the law applies given those facts. These letters of interpretation are guidance documents. They do not have the force and effect of law and are not meant to bind the public in any way. They are intended only to provide information to the public regarding existing requirements under the law or agency policies.
Understanding NHTSA’s Online Interpretation Files
NHTSA makes its letters of interpretation available to the public on this webpage.
An interpretation letter represents the opinion of the Chief Counsel based on the facts of individual cases at the time the letter was written. While these letters may be helpful in determining how the agency might answer a question that another person has if that question is similar to a previously considered question, do not assume that a prior interpretation will necessarily apply to your situation.
- Your facts may be sufficiently different from those presented in prior interpretations, such that the agency's answer to you might be different from the answer in the prior interpretation letter;
- Your situation may be completely new to the agency and not addressed in an existing interpretation letter;
- The agency's safety standards or regulations may have changed since the prior interpretation letter was written so that the agency's prior interpretation no longer applies; or
- Some combination of the above, or other, factors.
Searching NHTSA’s Online Interpretation Files
Before beginning a search, it’s important to understand how this online search works. Below we provide some examples of searches you can run. In some cases, the search results may include words similar to what you searched because it utilizes a fuzzy search algorithm.
Single word search
Example: car
Result: Any document containing that word.
Multiple word search
Example: car seat requirements
Result: Any document containing any of these words.
Connector word search
Example: car AND seat AND requirements
Result: Any document containing all of these words.
Note: Search operators such as AND or OR must be in all capital letters.
Phrase in double quotes
Example: "headlamp function"
Result: Any document with that phrase.
Conjunctive search
Example: functionally AND minima
Result: Any document with both of those words.
Wildcard
Example: headl*
Result: Any document with a word beginning with those letters (e.g., headlamp, headlight, headlamps).
Example: no*compl*
Result: Any document beginning with the letters “no” followed by the letters “compl” (e.g., noncompliance, non-complying).
Not
Example: headlamp NOT crash
Result: Any document containing the word “headlamp” and not the word “crash.”
Complex searches
You can combine search operators to write more targeted searches.
Note: The database does not currently support phrase searches with wildcards (e.g., “make* inoperative”).
Example: Headl* AND (supplement* OR auxiliary OR impair*)
Result: Any document containing words that are variants of “headlamp” (headlamp, headlights, etc.) and also containing a variant of “supplement” (supplement, supplemental, etc.) or “impair” (impair, impairment, etc.) or the word “auxiliary.”
Search Tool
NHTSA's Interpretation Files Search
| Interpretations | Date |
|---|---|
ID: aiam4550OpenMr. J. E. Carr Product Safety & Environmental Control Caterpillar Inc. Peoria, IL 61629; Mr. J. E. Carr Product Safety & Environmental Control Caterpillar Inc. Peoria IL 61629; "Dear Mr. Carr: This letter responds to your inquiry of April 29, 1988 asking this agency for an interpretation of Standard 124, Accelerator Control Systems, as it applies to the components of a diesel truck engine and accelerator control components described in your letter. I apologize for the delay in this response. With your letter, you provided diagrams of three different accelerator control systems and fuel metering devices for a diesel engine. The first system (Type I in your letter) was a purely mechanical system. In this system, the linkage from the accelerator pedal connects to a mechanical governor. This governor is a device that responds to pedal displacement, and causes a rack to move, thereby controlling the flow of fuel from fuel injector pumps into the engine cylinders. The second and third systems described in your letter operate through an electrical-mechanical sequence. In the second system (Type II in your letter), mechanical linkage from the accelerator pedal connects to an electronic pedal position sensor. When the vehicle operator puts pressure on the accelerator pedal, this sensor converts that movement into an electrical signal. The electrical impulse travels through a wire to an engine control module (ECM). The ECM interprets pedal position and engine speed from the sensor impulse, and determines how much fuel must go to the engine cylinders either to maintain or reduce speed in consequence of pedal movement. In turn, the ECM sends a signal to a motor which moves a fuel rack to control the flow of fuel from the injector pumps into the engine cylinders. In the system you call Type III, the ECM sends a signal directly to individual fuel injector pumps without the intervention of a rack. Otherwise, Type II and III are the same. On October 28, 1988, at the agency's invitation, you met with us to further explain the background information for this request and why Caterpillar believes that particular components were included in either the accelerator control system or the fuel metering device. During the course of that meeting, you agreed with us that Caterpillar's principal concern was not whether any particular component was part of the accelerator control system or the fuel metering device. Instead, you were concerned with the requirement that the throttle 'shall return to idle' under specified conditions. You explained that your ECM is designed to shut off the engine, rather than return the throttle to idle, during many failure modes. We conclude that the requirement that the throttle 'return to idle' is satisfied by a system that shuts off the engine in the specified circumstances. As S2 of Standard 124 makes clear, the purpose of the standard is to prevent runaway vehicles when certain malfunctions occur in the accelerator control system. If such malfunctions do occur, the standard ensures that the engine will not continue at a high speed, but will return to idle, so that the driver can safely brake the vehicle and get it off the road. In both the Type II and III systems referred to in your letter, the agency understands that a failure in the ECM circuitry, or a failure of the components that respond to the ECM, will either return the throttle to idle or shut down the engine. Either of these results would serve the purpose of Standard 124. Therefore, we interpret the phrase 'return to idle' to be satisfied by returning to idle or going beyond that throttle position to shut off the engine. Accordingly, based on the information you have provided, it appears that your Type II and III systems would comply with Standard 124 regardless of whether the ECM and other components are considered part of the acclerator control system or the fuel metering device. I hope you find this information helpful. If you have further questions, please call Joan F. Tilghman of my staff at (202) 366-2992. Sincerely, Erika Z. Jones Chief Counsel"; |
|
ID: aiam3295OpenMr. Martin D. Davis, Meon, Inc., 221-18 Merrick Boulevard, Springfield Gardens, NY 11413; Mr. Martin D. Davis Meon Inc. 221-18 Merrick Boulevard Springfield Gardens NY 11413; Dear Mr. Davis: This is in response to your letter of May 12, 1980, requestin interpretation of paragraph (c)(2)(iii) of the Uniform Tire Quality Grading Standards (49 CFR S 575.104). That paragraph provides that to qualify as a limited production tire a tire cannot have been listed as a vehicle manufacturer's recommended tire size designation for a new motor vehicle produced in or imported into the United States in quantities greater than 10,000 during the preceding calendar year. You ask whether a tire meets this requirement if its size is recommended for use on several new vehicles, none of which is produced in quantities greater than 10,000 yearly, but which in the aggregate account for annual production in excess of 10,000 vehicles.; Paragraph (c)(2)(iii) refers to '*a* vehicle manufacturer's recommende tire size designation (emphasis added)' and '*a* new motor vehicle (emphasis added)', indicating that the 10,000 vehicle limitation refers to the production or importation of a particular vehicle model, rather than the total of all models for which the tire size is recommended. Thus, if a tire's size is recommended for use on several vehicle models, none of which is produced in or imported into the United States in quantities greater 10,000 during the calendar year preceding the year of the tire's manufacture, the tire would meet the criterion of paragraph (c)(2)(iii).; Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam0840OpenMr. Richard Stevens, Cody Chevrolet, Inc. Barre-Montpelier Road, Montpelier, VT 05602; Mr. Richard Stevens Cody Chevrolet Inc. Barre-Montpelier Road Montpelier VT 05602; Dear Mr. Stevens: This is in reply to your letter of August 1, 1972, to the attention o Mr. Jerome Palisi of our White Plains, New York Office, concerning certification requirements for a vehicle which you describe and indicate will be used by a college to transport ball teams and school personnel, but will not be equipped with flashing lights or other special school bus equipment. You apparently wish to know whether you must consider this vehicle as a school bus for purposes of certification to Federal requirements.; 'School bus' is defined in the motor vehicle safety standards to mean bus 'designed primarily to carry children to and from school, but not including buses operated by common carriers in urban transportation of school children' (49 CFR 571.3). Based upon the description you provide, the NHTSA would not consider the vehicle you describe to be a school bus. For purposes of certification to Federal requirements (49 CFR Parts 567 and 568), there, 'gross vehicle weight rating' should not be computer under the minimum values specified for school buses. In addition, the requirement that vehicle type be inserted on the certification label should be met in inserting, 'BUS.'; This letter should not be construed to mean that the NHTSA takes position as to whether this vehicle need, under State law, conform to requirements for school buses. The State must determine the scope and application of its own laws.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam1752OpenMr. John C. Bennett, Chairman of the Board, Utility Trailer Manufacturing Co., City of Industry, CA 91749; Mr. John C. Bennett Chairman of the Board Utility Trailer Manufacturing Co. City of Industry CA 91749; Dear Mr. Bennett: This responds to your January 8, 1975, request for reconsideration o our determination, in a January 3, 1975, letter to Mr. J. B. Markovich, that a bulk transport trailer designed for transporting farm commodities from the field to processing plants over private and public roads does not qualify for exemption from Standard No. 121, *Air brake systems*, as an agricultural vehicle.; There is no specific exemption for agricultural machinery in th language of the 'National Traffic and Motor Vehicle Safety Act of 1966' (15 U.S.C. 1391 et seq.), and there is little legislative history on the subject. We have concluded that Congress only intended to exclude agricultural machinery that is designed for working on the fields--implements of husbandry--and whose on-road use is strictly limited, at low speeds, and only incidental to its main function.; The NHTSA has interpreted the definition of 'motor vehicle' to agre with this Congressional intent. Our criteria for a 'non-motor vehicle' have been (1) a maximum speed not exceeding 20 mph, and (2) an abnormal configuration which distinguishes it from the traffic flow. These criteria separate 'agricultural machinery' from those vehicles which are related to agriculture but use the highways as a primary purpose.; The NHTSA does not interpret 'motor vehicle' to exempt a vehicle whic has a highway speed capability, even if it uses the highway infrequently. For example, house trailers are subject to safety standards although they sometimes use the highways only once to be moved to a permanent homesite. Mobile cranes and drill rigs which use the highways between job sites are another vehicle type which has also been determined to be a motor vehicle. The important consideration is that their configuration permits unlimited use of the highways.; From your description, your bulk transport trailers are capable o highway speed and use the highway in the same way as other air-braked full trailers. Accordingly, your request for reclassification is denied.; You mentioned difficulty in meeting Standard No. 121's parking brak requirements. I enclose a copy of correspondence on this same matter with a railroad company that finds it necessary to manually release parking brakes under some circumstances.; Sincerely, |
|
ID: aiam4100OpenRobert R. Clark, Esq., Tabbert & Capehart, One Indiana Square, Suite 1500, Indianapolis, IN 46204; Robert R. Clark Esq. Tabbert & Capehart One Indiana Square Suite 1500 Indianapolis IN 46204; Dear Mr. Clark: This responds to your letter dated October 21, 1985, inquiring abou the certification responsibilities under federal law of your client, a new car dealer. You stated in your letter that your client plans to convert new automobiles into limousines. These limousines would then be sold wholesale to dealers.; The relevant federal statute is the National Traffic and Motor Vehicl Safety Act of 1966, as amended (15 U.S.C. 1391 *et seq*.). Under section 103 of the Act, this agency issues Federal motor vehicle safety standards and regulations applying to motor vehicles and their equipment.; As we understand the facts stated in your letter, the automobiles wil be completed by the original manufacturer who will certify that they meet all applicable Federal motor vehicle safety standards. Your client plans to alter the automobiles prior to their first purchase for purposes other than resale.; Your client's plan to convert automobiles would make him an alterer subject to the requirements of 49 CFR Part 567.7, *Certification*. An alterer is a person who alters a previously certified vehicle by means other than the addition, substitution, or removal of readily attachable components or minor finishing operations, or in such a manner that the vehicle's stated weight ratings are no longer valid. If the alteration is performed before the first purchase of the vehicle for purposes other than resale, the alterer must supplement the certification label by affixing an additional label stating that the vehicle as altered conforms to all applicable Federal motor vehicle safety standards and containing the firm or individual name of the alterer.; An alterer is also considered a manufacturer for the purposes o notification and recall for defects or noncompliance under the Act and is subject to the requirements of 49 CFR Part 573, *Defect and Noncompliance Reports*.; In addition, please note that your client should take care in makin the conversions not harm the vehicles' safety features. Under section 108 of the Act, a manufacturer, distributor, dealer, or motor vehicle repair business must not knowingly render inoperative, in whole or in part, any device or element of design which is installed on or in a motor vehicle or item of motor vehicle equipment in compliance with an applicable Federal motor vehicle safety standard. Your client would be subject to this prohibition which applies both before and after the first purchase of a motor vehicle for purposes other than resale.; I hope this information is helpful to you. Sincerely, Erika Z. Jones, Chief Counsel |
|
ID: aiam1302OpenMr. Charles Leeds, Bankers Trust Company, 1775 Broadway, New York, NY 10019; Mr. Charles Leeds Bankers Trust Company 1775 Broadway New York NY 10019; Dear Mr. Leeds: This is in reply to your letter of September 17, 1973, which ask whether a bank must make an odometer disclosure statement upon transfer to an auctioneer of a repossessed vehicle in which the bank has only a security interest.; To the extent that the bank is acting in the place of the repossesse owner, and in the absence of any other party available to make a statement, it is our opinion that the bank is acting as transferor and should make the disclosure specified in Part 580. Normally the bank does not know that the odometer is inaccurate and should only fill in the blank with the recorded mileage. The bank could authorize its collection agency to actually make the disclosure.; Yours truly, Richard B. Dyson, Assistant Chief Counsel |
|
ID: aiam3411OpenMr. Thomas W. Elkins, Secretary, North American Classics Corporation, 1851 Austin, Troy, MI 48084; Mr. Thomas W. Elkins Secretary North American Classics Corporation 1851 Austin Troy MI 48084; Dear Mr. Elkins: This is in reply to your letter of April 15, 1981, asking two question with respect to the temporary exemption provisions of the National Traffic and Motor Vehicle Safety Act (15 U.S.C. 1410) and implementing regulations (49 CFR Part 555).; Your first question is: >>>(1) Assuming North American Classics designs the total engineerin of the Thunderbird reproduction, selects all components to be incorporated therein, retains primary control over quality control, testing, FMVSS compliance in design, and manufacturing assembly sequence, and markets the produced vehicles on its behalf to its customers, does North American Classics remain eligible to apply for exemption from meeting certain FMVSS requirements for this vehicle in the event that the actual responsibility for the assembly of the vehicles is contracted by North American Classics to a manufacturer which produces more than 10,000 motor vehicles per year?<<<; Although you have not said so I understand from Taylor Vinson that th manufacturer with whom you would contract is a foreign corporation which has never produced motor vehicles for the American market. We also understand that it may be less expensive to have your car built abroad than at home.; Under the circumstances you describe, the foreign corporation appear to be nothing more than your agent in fabricating the vehicles and returning them for sale. This would not affect your eligibility for exemption. You would retain the responsibility for certification, as we understand it, even though the name of the foreign manufacturer would also appear on the certification label, as required by 49 CFR 567.4(g)(1).; Your second question is: >>>(2) In the event that North American Classics enters into a agreement to have such vehicles produced or assembled by a major automotive manufacturer, who would not be so eligible, and if such agreement provides for the sharing of profits derived from the sales of the finished product between North American Classics and such manufacturer, as a means of providing North American Classics assurance that projected costs of such manufacturer do not increase beyond North American Classics' ability to survive financially, in such event would North American Classics retain its eligibility status, assuming North American Classics retains control of the functions outlined in paragraph?<<<; We do not believe that a profit-sharing agreement *per se* would affec your eligibility for exemption. Were the foreign company to receive a majority share of the profits or to purchase sufficient stock in your company to give it effective control, however, we would have substantial questions about which party actually exercises primary control.; I hope this answers your questions. Sincerely, Frank Berndt, Chief Counsel |
|
ID: aiam3041OpenMr. J. C. Eckhold Ford Motor Company The American Road Dearborn, Michigan 48121; Mr. J. C. Eckhold Ford Motor Company The American Road Dearborn Michigan 48121; Dear Mr. Eckhold: This is in response to your letter of May 23, 1979 requesting an interpretation of Federal Motor Vehicle Safety Standard No. 101-80, Controls and Displays. Specifically, you requested a clarification of Section 5.3.3 which states that each tell-tale and its identification must be 'visible to the driver under all daytime and nighttime conditions.' You indicated that under certain conditions the intensity and color characteristics of sun lighting could cause transitory reflections that obscure either the intensity or color, or both, of the tell-tale. It is the interpretation of the National Highway Traffic Safety Administration that the manufacturer must manufacture a tell-tale with a light intensity that ensures visibility under the most adverse general lighting conditions. This means that the tell-tales and their identification need not be visible to the river when the tell-tales are struck by direct sunlight. Since conditions such as these are typically short-lived, the NHTSA does not believe that the length of time the driver may be unable to view the tell-tales is significant enough to warrant requiring the manufacturer to prevent their occurrence. Sincerely Frank Berndt Chief Counsel; |
|
ID: aiam4784OpenMr. William T. Mullen Undersheriff of McHenry County, Illinois 2200 N. Seminary Ave. Woodstock, IL 60098; Mr. William T. Mullen Undersheriff of McHenry County Illinois 2200 N. Seminary Ave. Woodstock IL 60098; "Dear Mr. Mullen: This responds to your letter asking about Federa requirements for safety belts in police cars. Specifically, you asked if your police department could legally remove the automatic belts that are installed and replace them with manual lap/shoulder safety belts. You stated that the reasons for making such a substitution would be to alleviate two problems your police officers have experienced with the automatic belts that were not present in older models that had manual lap/shoulder belts at the front seating positions. First, you said that the automatic belts result in a blind spot on the driver's left side. Second, you said that the automatic belts 'prevent left arm movements' of your taller officers. I appreciate this opportunity to respond to your concerns. I have enclosed copies of two previous letters we have written on the subject of removing or replacing occupant protection features from police cars. The first of these is a July 29, 1985 letter to Corporal Frank Browne and the other is a May 25, 1989 letter to Senator Harry Reid. These letters explain that new vehicles purchased by police departments must be certified as complying with the occupant crash protection standard (Federal Motor Vehicle Safety Standard No. 208). All cars manufactured on or after September 1, 1989 must provide automatic crash protection for front seat occupants. To date, manufacturers have provided automatic crash protection either by installing air bags or automatic safety belts. General Motors, the manufacturer of the police cars in question, has chosen to comply with the requirement for automatic crash protection by installing automatic safety belts in these cars. Federal law prohibits any manufacturer, distributor, dealer, or motor vehicle repair business from replacing the automatic belts in these police cars with manual lap/shoulder belts. Thus, none of these commercial entities could make such a replacement on behalf of the County without violating Federal law. However, Federal law does not prohibit individual vehicle owners from removing safety features from their own vehicles. Thus, McHenry County itself can replace the automatic belts in its own cars without violating any Federal law, just as any resident of McHenry County can remove any safety equipment they like from their own vehicles without violating any Federal laws. Such actions may, however, violate the laws of the State of Illinois. I recommend that you carefully consider the effects of replacing the automatic belts in your police cars, even though Federal law does not prohibit the County itself from making these modifications to its own vehicles. The automatic belts in these cars help to assure safety belt use by police officers on the job. Particularly since the McHenry County police officers face the possibility of becoming involved in high speed pursuit situations, we believe it is important that they use safety belts for effective protection in case of a crash. If you decide to replace the automatic belts in these vehicles with manual lap/shoulder belts, we would urge you to take some actions to assure that the police officers will use the manual lap/shoulder belts every time they ride in the police cars. I hope this information is helpful. If you have any further questions or need some additional information on this subject, please let me know. Sincerely, Paul Jackson Rice Chief Counsel Enclosures"; |
|
ID: aiam1586OpenMr. R.W. Cheetham, Director of Quality Assurance, Armstrong Rubber Company, 500 Sargent Drive, New Haven, CT 06507; Mr. R.W. Cheetham Director of Quality Assurance Armstrong Rubber Company 500 Sargent Drive New Haven CT 06507; Dear Mr. Cheetham: This will confirm that the suggested defect notification letter enclosed in your letter of August 14, 1974, meets the requirements of 49 CFR Part 577.; We appreciate your taking this action with respect to the Steel Belte Surveyor 78 tire.; Yours truly, Frank Berndt, Acting Chief Counsel |
Request an Interpretation
You may email your request to Interpretations.NHTSA@dot.gov or send your request in hard copy to:
The Chief Counsel
National Highway Traffic Safety Administration, W41-326
U.S. Department of Transportation
1200 New Jersey Avenue SE
Washington, DC 20590
If you want to talk to someone at NHTSA about what a request for interpretation should include, call the Office of the Chief Counsel at 202-366-2992.
Please note that NHTSA’s response will be made available in this online database, and that the incoming interpretation request may also be made publicly available.